It is known to treat textiles, particularly textile materials of cellulosic fibers, with a variety of phosphorous-containing organic compounds. Known materials of this type include, for example, tris(aziridinyl)phosphine oxide, tetrakis(hydroxymethyl)phosphonium chloride, and tris (2,3-dibromyopropyl)phosphate. Background information is summarized in "The Chemistry and Use of Fire Retardants" by J. W. Lyons, Wiley-Interscience Publishers, New York, 1970.
Particular difficulties arise in flameproofing textiles of mixed fiber content, such as blends of cotton and polyethylene terephthalate fibers. The state of the art is summarized by G. S. Tesoro in Textile Chemists and Colorists, 5 (11), 253 (1973); impregnation of fabrics with known chemical finishing systems is not completely satisfactory in practice (a) for treatment of fabrics containing blends of cotton and polyester fibers, (b) for achievement of high levels of effectiveness and permanance of the flame retarding agents, (c) for retention of the aesthetic characteristics of the original unmodified fabric, (d) for development of flame retardancy together with durable press performance properties, and (e) for retention of high levels of strength properties in the chemically-modified, flame-retardant fabric.
Processes for improving textiles composed of cellulose fibers and synthetic fibers have been suggested in which the textiles are subjected to the combined action of tetrakis(hydroxymethyl)phosphonium salts and halogenated alcohols, aldehydes, amines, ketones, and/or carboxylic acids ("The Chemistry and Uses of Fire Retardants," J. W. Lyons, Wiley-interscience Publishers, 1970). Polymerizable compounds such as acrylamide can also be used in combination with tetrakis(hydroxymethyl)phosphonium chloride (THPC). In flameproofing of substrates such as wood (U.S. Pat. No. 2,927,050, J. D. Guthrie). Bis (2-chloroethyl) vinylphosphonate can be copolymerized with acrylamide, N-methylol acrylamide, or acrylonitrile on polypropylene fibers to achieve the flame retardancy (A. Adler and W. Brenner, Nature, 225, 60 (Jan. 3, 1970)). Organic phosphorus compounds resulting from the combination of two moles of THPC with one mole of N-methylol acrylamide may be prepared and subsequently applied to textiles, especially those including cellulosic fibers, for the purpose of flameproofing (U.S. Pat. No. 3,709,940, W. Flugel).
These and related processes of the prior art leave much to be desired in satisfying the requirements enumberated above. In addition, the above reactions utilizing vinyl monomers involve a pre-polymerization or pre-reaction of these monomers with other reagents prior to application to the fabric (cf. Guthrie and Flugel). In other cases the application of the vinyl monomer to the fabric necessitates the use of supplementary solvents (cf. Adler and Brenner), low efficiency of conversion of monomers to fixed polymer, and relatively low durability of the effectiveness of the treatment.
The objects of this invention are: (a) chemical finishing treatments that may be applied to textile fabrics from totally aqueous systems without the necessity for employing supplementary solvent materials in order to produce improved flame-retardant textiles and (b) chemically-modified textile products that exhibit high flame retardancy-high permanency of the effects of the treatment, combinations of durable press properties with flame retardancy, and good retention of strength properties of the textile composition.